Malicious PDF — malware analysis report

Static analysis result for SHA-256 439acc28120de2e3…

MALICIOUS

PDF

77.4 KB Created: 2021-06-13 10:23:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 8c1cbbc0c76cc4986b066e9141dfed29 SHA-1: b000cd9d2f0c16075a9c7011639da1438a2c06a6 SHA-256: 439acc28120de2e3637245d633503a8b8d48a77bed77213489e33fc63d01c0a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple links to what appears to be a link farm, hosted on compromised WordPress sites, designed to trick users into downloading a file by disguising it as a student's book. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://inwebjor.ru/uplcv?utm_term=headway+5th+edition+intermediate+student%2527s+book+pdf PDF link annotation
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/vdgtd359df0vnha03s8po93rko/93386645682.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/u7bn5nmks4htc71gabmf7ai4p0/11546329326.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160719698c7a97---4373882568.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bb03157047---risiriduporaje.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160bbbe982977a---19202294119.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/5banuuna29abvt59oro6okc52r/9848351218.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/71893574672.pdfIn PDF document text
    • http://aj-logistics.com/stock/userfiles/file/41028379027.pdfIn PDF document text
    • http://slhs1958.com/clients/18590/File/vavuwinenipatumegumu.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/iufm7rr9sjvao5hrp2ui4i392e/48772794615.pdfIn PDF document text
    • https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/bb9d887f3b5b79cb8e4fc246dd59b0f4/92221910632.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/35ebea6dbdf44ae2560b715287d2dd89/14731015197.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607362bc00a4e---dedolalijepevunasetole.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6015aaad9d---sozurawaburorup.pdfIn PDF document text
    • https://moveo-sport.pl/userfiles/file/70974136500.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D4 5768 bytes
SHA-256: b5ed50d75eb1576d798dd2ae2e46ae46101f67c07686aac0c7cf339ee48b6858
font_01_sfnt_off0000f668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF668 15480 bytes
SHA-256: 3305e00e7e2d7129753368679f6485a40d791e60e5b9a220748b23f252634187

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